The present invention relates to a method for producing a bulked composite yarn composed of an inelastic yarn component and an elastic yarn component. A process of this general type is disclosed in U.S. Pat. No. 3,940,917.
In a known process of the described type, a thermoplastic yarn, i.e., a filamentary yarn having a relatively low elasticity, is brought together with a spandex elastic yarn which has a comparatively high elasticity of for example more than ten times that of the inelastic yarn component. The two yarn components are then guided through an air nozzle and withdrawn therefrom in a manner such that the overfeed of the relatively inelastic yarn component is zero. The resulting composite yarn is characterized by having the filaments of the inelastic yarn component entangled about the elastic yarn component in intermittent zones of entanglement which are separated by relatively non-entangled zones. This process has the disadvantage that the air jet treatment can only provide for the desired intensive and uniform combination of the two components when the two components are guided through the air jet at a relatively slow speed, or when a particularly intensive air jet treatment is employed which involves a high pressure and a high throughput of the air.
It is an object of the present invention to provide a method of the described type wherein a high quality composite yarn with intensive entanglement of the individual filaments is produced, and which is carried out at high yarn speeds and low energy consumption.